Prime-Line 3/8 in.-16 x 1-1/2 in. Zinc Plated Case Hardened Steel Serrated Flange Bolts (25-Pack)

Flange bolts feature a built-in washer under the bolt head that helps to distribute the clamping load over a larger area. This 1-piece design eliminates the need of a separate washer under the bolt head and is preferable for some applications as it can be more efficient and easier to use. A washer is still needed on the nut side unless using a flange nut. The serrations under the flange bite into the surface and help to resist loosening due to vibration.